Acid fading inhibition



Patented Oct. 15, 1946 2,409,251 ACID FADING INHIBITION Cyril M. Croft, and Thomas s. Waller, Cumberland, Md., assignors to Celanese Corporation of America, a corporation of Delaware No Drawing. Application January 9, 1943,

" Serial No. 471,880

7 Claims. 1

This invention relates to the treatment of dyed ,extile materials and relate more particularly to the preparation of dyed fabrics made of or containing yarns having a basis of cellulose acetate or other organic derivative of cellulose having colorations thereon fast to acid fading.

An object of our invention is to provide a novel method of treating colored fabrics having a basis of cellulose acetate or other organic derivative of cellulose yarns which have been dyed with colors ordinarily not fast to acid fumes to inhibit the fading of said colored textile materials when exposed to such fumes.

Another object of our invention is to obtain colored fabrics having a basis of cellulose acetate or other organic derivative of cellulose yarn, which fabrics are highly resistant to acid fading.

Other objects of our invention will appear from the following detailed description.

In the coloration of textile materials it is very desirable that the colors produced on the materials be as fast as possible to light, washing and to other agencies such as acid fumes. Many dyestuffs yield on organic derivative of cellulose materials desirable shades which are fast to washing but these dyestuffs often suffer from a lack of fastness to acid fumes. When fabrics to which these dyestuffs have been applied are exposed to acid fumes, for example, the products of combustion of coal, gas, etc., the color undergoes a change in shade. acid fading. The change which occurs may be a dulling of the brightness of the shade in some instances, and in others there may be a definite change in color. This undesirable effect is frequently observed in the case of many anthraquinone dyestufis which yield valuable blue colors on organic derivative of cellulose materials. When fabrics dyed with these colors are exposed to acid fumes the colors change from a pure blue shade to one having a reddish cast. One continued exposure to the acid fumes the blue color may even change to a pink color. Such changes naturally restrict the range of usefulness of these dyestuffs and methods of increasing the resistance of these dyes to acid fading are of great commercial importance.

We have now discovered that the acid fading characteristics of organic derivative of cellulose textile materials dyed with dyestuffs which are ordinarilly not fast to the action of acid fumes may be substantially improved by subjecting the dyed textile materials to treatment with aqueous solutions of triethanolamine containing a solvent or swelling agent for the organic derivative of cel- This change is usually referred to as lulose materials. The triethanolamine is caused to penetrate the structure of the textile material by reason of the action of the solvent or swelling agent by means of which it is applied, and the treated material obtained, after drying, exhibits a greatly enhanced resistance to acid fading. The increased resistance to acid fading imparted to said organic derivative of cellulose materials by our novel process enables said materials to render far more satisfactory service. The materials may be exposed to those concentrations of acid fumes or combustion products normally present in the atmosphere for extended periods without any change being observed in the shade or brightness of the coloration. Not only are the above advantages obtained, but the materials may be dry cleaned in the usual manner after our novel treatment without any substantial change in their resistance to acid fading.

Varying amounts of triethanolamine may be placed on the textile materials in order to improve their acid fading characteristics. We have found that from 0.75 to 5.0% yields satisfactory results, and excellent results are obtained when about 2.0% of triethanolamine is incorporated in the organic derivative of cellulose materials.

The amount of triethanolamine applied to the textile materials in accordance with our novel process may be varied conveniently by employing different concentrations of triethanolamine in the solutions from which it is applied. Solutions containing from 1.0 to 5.0% by weight of triethanolamine are suitable; the higher the concentration the more triethanolamine will be put on the textile material.

The solutions from which the triethanolamine is applied may contain from 15.0 to 70.0% of an organic compound having at least a solvent or swelling action on the organic derivative of cellulose materials. Suitable compounds having a solvent or swelling action on the organic derivative of cellulose materials are, for example, ethyl a1- cohol, butyl alcohol, isopropyl alcohol, or acetone. Ethyl alcohol is preferably employed in aiding the triethanolamine to penetrate the textile material and may be present in the aqueous solution in concentrations of from 15.0 to '7 0%.

In order further to illustrate our invention but without being limited thereto the following example is given:

Example- A cellulose acetate fabric, dyed in a blue shade with 1% of 1:4 di-methylamino-anthraquinone, is padded with a solution comprising 20 parts by weilht of triethanolamine, 320 parts by weight of ethyl alcohol and 600 parts by weight of water.

The amount of triethanolamine retained on thefabric is 1.38% by weight. A portion of the treated fabric is immersed in perchlorethylene cleaning solvent for 15 minutes, squeezed and allowed to dry. Samples of dyed fabric which have not been treated with triethanolamine are exposed to acid fumes simultaneously with samples of the treated and cleaned fabric. After the samples have been exposed to acid fumes for 40 hours, it is observed that there is only a slight reddening in the shade of the treated, cleaned fabric. The untreated fabric, however, is faded completely to pink by the acid fumes.

\ While our invention has beenmore particularly described in connection with the treatment of a fabric having a basis of cellulose acetate, yarns as well as other textile materials made of or containing other organic derivative of cellulose may be treated in like manner to inhibit acid fading. Such other organic derivatives of'cellulose are cellulose ester such as cellulose propionate, cellulose butyrate and mixed esters such as cellulose acetate-propionate and cellulose acetatebutyrate, and cellulose ethers such as ethyl cellulose and benzyl cellulose.

It is to be understood that the foregoing detailed description is given merely by way of illustration and that many variations may be made therein without departing from the spirit of our invention.

Having described our invention, what we desire to secure by Letters Patent is:

1. Process for improving the fastness of colorations on dyed organic derivative of cellulose textile materials to acid fading, which comprises impregnating said colored organic derivative of cellulose textile material with an aqueous solution of triethanolamine containing an alcohol having at least a solvent or swelling action on said organic derivative of cellulose material without effecting any substantial change in the serimetric characteristics of said textile material.

2. Process for improving the fastness of colorations on dyed cellulose acetate textile materials to acid fading, which comprises impregnating said colored cellulose acetate textile material with an aqueous solution of triethanolamine containing an alcohol having at least a solvent or swelling action on said cellulose acetate material without eflecting any substantial change in the serimetric characteristics of said textile material.

3. Process for improving the fastness of colorations on dyed organic derivative of cellulose textile materials to acid fading, which comprises impregnating said colored organic derivative of cellulose textile material with an aqueous solution of triethanolamine containing ethyl alcohol without effecting any substantial change in the serimetric characteristics of said textile material.

4. Process for improving the fastness of colorations on dyed cellulose acetate textile materials to acid fading, which comprises impregnating said colored cellulose acetate textile material with an aqueous solution of triethanolamine containing ethyl alcohol without effecting any substantial change in the serimetric characteristics of said textile material,

5. Process for improving the fastness of colorations on dyed cellulose acetate textile materials to acid fading, which comprises impregnating said colored cellulose acetate textile material with an aqueous solution of triethanolamine containing from 15.0 to 70.0% by weight of ethyl alcohol without effecting any substantial change in the serimetric characteristics of said textile material.

6. Process for improving the fastness of colorations on dyed cellulose acetate textile materials to acid fading, which comprises impregnating said colored cellulose acetate textile material with an aqueous solution containing from 15.0 to 70.0% by weight of ethyl alcohol and from 1.0 to 5.0% of triethanolamine.

7. Process for improving the fastness of colorations on dyed cellulose acetate textile materials to acid fading, which comprises impregnating said colored cellulose acetate textile material with an aqueous solution containing from 15.0 to 70.0% by weight of ethyl alcohol and from 1.0 to 5.0% by weight of triethanolamine, whereby from 0.75 to 5.0% of said triethanolamine by weight is incorporated in said cellulose acetate textile material.

CYRIL M. CROFT. THOMAS S. WALLER. 

